Gas turbine combustors are typically provided with floating collar or seal assemblies for mounting igniters or fuel nozzles to the combustor, in order to facilitate movement of igniters or fuel nozzles relative to the combustor shell and/or permit thermal growth differential therebetween during engine operation. The floating collar may also reduce loading on the igniter, fuel tubes and fuel nozzles mounted to the combustor thereby, which might otherwise be generated from vibration, thermally induced and stress induced combustor movement relative to the adjacent supporting structures.
Such floating collars may be retained within enclosed bosses mounted to the combustor. However, such enclosed bosses may be prone to obstruction by sand or other airborne particulate debris. Accordingly it is desirable to prevent particulate accumulation in spaces surrounding a floating collar.